A posterior polar cataract is a type of congenital cataract that occurs in the central cortex adjacent to the posterior capsule. There is an increased risk of a posterior capsular tear during cataract surgery because a capsular defect is often present.
Therefore, it is important to carefully evaluate the cataract and posterior capsule during the slit lamp exam preoperatively. Even if a discrete capsular defect is not detected, (usually visible as small vacuole(s)), the increased risk of a capsular complication should be discussed with the patient during the informed consent process. During surgery, specific techniques can help reduce the risk of capsular damage and possible vitreous loss:
- No hydrodissection—hydrodissection with a fluid wave passing across the posterior capsule increases the risk of blowing out the posterior capsule. Therefore, only hydrodelineation should be performed. In the video, I gently hydrodissect the anterior cortex to facilitate cortical removal, but I do not allow the fluid to pass posterior to the lens equator. Then I hydrodelineate by passing the cannula deeper towards the nucleus.
- Inspect the posterior capsule—this should be done after each step (i.e., hydrodelineation, phacoemulsification, and cortical cleanup) to identify if and when a capsular defect has occurred so the appropriate action can be performed to minimize posterior migration of lens material and/or vitreous loss.
- Minimize capsular stress—this can be accomplished in a variety of ways including lowering the irrigation bottle height, reducing flow and vacuum settings, maintaining a stable anterior chamber (avoid surge and chamber bounce), and minimizing manipulations of the lens. I prefer to use a chip and flip (for cataracts with a small nuclear component) or vertical chopping (for cataracts with a large nuclear component) technique for phacoemulsification.
- No polishing—do not attempt to polish any residual posterior capsular plaque in the area where the posterior polar cataract was located. This seemingly benign and gentle maneuver can easily create a tear in the weakened/defective posterior capsule. Even though leaving a small plaque may affect the patient’s vision postoperatively, it is much better to just perform a laser posterior capsulotomy in the future. In the video, I do remove two small cortical remnants by polishing, but these are not part of the residual posterior polar cataract visible as a central plaque on the posterior capsule. I do not touch this; instead, I completed the procedure by inserting an IOL in the bag, and 3 months later I performed a Nd:YAG laser capsulotomy.